The present invention relates to a technique for measuring the shapes of micropatterns formed in semiconductor memories, integrated operational circuits and other semiconductor devices.
Aimed at achieving higher integrated semiconductor devices, wiring pattern width is remarkably becoming narrower. New resist materials are under development for use with ArF (argon fluoride)-based short-wavelength exposure light in order to form micropatterns, as described in Japanese Patent Laid-open No. 2000-241964. On the other hand, length-measuring SEM (Scanning Electron Microscopy) is known as a technique for measuring the width of a micropattern formed in a semiconductor device. The length measuring SEM emits an electron beam and uses the amplitude of a signal obtained by detecting generated secondary electrons and reflected electrons. One example application method is disclosed in Japanese Patent Laid-open No. 2001-272219.
Although the length-measuring SEM can measure a very small width, it has a problem that irradiating a resist pattern made of such a material as mentioned above with an electron beam results in making the width of the pattern smaller.